The present invention relates to an apparatus for the packaging and sealing of an article within heat-shrinkable film of the so-called "centerfolded" type.
The apparatus according to the invention is particularly, but not exclusively, adapted for packaging books, magazines, office files, table, correspondence and all other papers requiring to be stored, despatched or sealed, also for purposes of secrecy.
Different kinds of apparatus for packaging material inside heat-shrinkable film are known.
A first type of apparatus consists structurally of the combination of a film sealing device between the opposite faces of which the article to be packaged has been placed, and a tunnel in which the film is heat-shrunk onto the article.
The film sealing device (sealing rod type) and the tunnel are disposed in-line and the article is fed through the tunnel by means of a conveyor, generally a roller conveyor.
Packaging apparatus of such type normally have large bulk dimensions and are suitable for high outputs and for the packaging mostly of relatively large articles.
In another type of packaging apparatus the sealing rods of the sealing device are incorporated in a closure of a chamber in which the heat-shrinking of the film is also performed by means of forced hot air circulation.
Such kind of packaging apparatus is for example described in U.S. Pat. No. 4,104,848, from which the relevant technology may be better understood.
Although it can be relatively small in size and is very satisfactory in operation, a packaging apparatus embodied according to U.S. Pat. No. 4,104,848 can be used in a manner such as to achieve operating speeds that counsel its use in certain specific sectors.
If used to package a small number of articles per day, its potential is wasted, and in some cases it may prove unwieldy.
The object of the present invention is to embody a packaging machine that has a highly compact structure, is economical to construct, extremely dependable in use and that can find a justified use even for relatively low outputs.